Manly....ok...ummm....leather streamers on the bar ends. Flat black paint (all over, just try to keep the paint off the rims and brake pads). A couple of spots of primer. When riding, act less intelligent.(or stupid, whichever way you want to take that). Wear a helmet with a flame paint job. Do not shave your legs. Carry around one of those big, leather weight lifting belts on your rack. Switch to rat-trap pedals.
When I think of more, I will let you know.